FIGURE 2.

Mesenchymal stromal cell (MSC) proliferation and migration capacity. In vitro proliferation of MSCs from chronic obstructive pulmonary disease (COPD) and non-COPD patients was followed over time. a) Time needed for cultures to become near-confluent and the number of MSCs that were obtained per passage were assessed. b) Population doubling time (PDT) was calculated by dividing the natural logarithm of 2 by the exponent of growth. Plots represent median, interquartile range, and minimum and maximum values. n=9 per group. c) Migration as assessed using electric cell-substrate impedance sensing (ECIS). MSCs were cultured in ECIS arrays in the presence of an electrical fence (EF), which prevented cell adherence across the electrode area. Resistance (at 500 Hz) and capacitance (at 40 kHz) were measured continuously and followed up to 15 h after removal of the electrical fence (t=0 h). Restoration of the resistance and capacitance to control values (corresponding to full coverage of the electrode) was used as a measure for migration capacity of MSCs. Normalised data were obtained by correcting for the resistance/capacitance values obtained in control wells without an electric fence, at the time the electric fence was removed (t=0 h). Data are presented as mean±sem. n=5–8 per group.